(1) Field of the Invention
This invention relates to oil well blowout control and more particularly to preventing the blow from tubing within a casing or through the drill stem of drill pipe.
(2) Description of the Related Art
As used herein, "oil well" is used to include wells producing either oil or gas.
Oil wells often have tremendous pressures deep within the earth. These pressures are normally controlled by the weight of mud within the well. However, certain times, unbalance occurs and it is possible for the well to blow, i.e., the pressure within the earth force the mud, gas, oil, and other fluids up with tremendous force. The fluids from within the earth may be forced up between the casing and the tubing (or between the well and the drill stem). There exist blowout preventers for controlling the flow of fluid in the annular space between the casing and tubing. Also, there is often a flow of fluid through the tubing (or drill stem) itself.
This application relates to preventing the flow of fluid from the tubing or drill stem. Normally, when working over the well, the tubing will be either removed from the well or run into the well a joint at a time. Normally, the tubing will be held above the surface of the ground with a collar on the end of the tubing. This is the case either when the tubing is being removed or run in the well.
Normally, the tubing and the collars will have standard dimensions. One standard size tubing used in oil field equipment is 23/8" outside diameter. This size tubing is used as an example in this application. However, it will be understood that there are other size tubings widely used in the oil field. Also, this invention is applicable to a drill stem which has its own sizes.
With 23/8" tubing, the collars will have a 3" outside diameter and a length of about 41/2" to 51/2".
Before this application was filed, the applicant was aware of the following United States patents:
______________________________________ Inventor U.S. Pat. No. ______________________________________ Thrift 1,323,660 Hamer 1,662,311 Arbon 1,713,364 Burris 1,874,889 Coone 3,958,642 Lissmyr 4,192,376 Delesandri 4,442,892 Buras et al 4,461,354 ______________________________________
Applicant believes the information found in these patents is not as pertinent as the information specifically discussed above. These inventions show other devices to perform similar tasks. However, applicant believes that the Examiner would be interested in any patent found by an experienced patent searcher.